Contacts and conductive traces are used in semiconductor devices to provide electrical connection. Since contacts and conductive traces are formed by different processing acts, it is necessary to tightly control photolithography and etching processes so that each contact connects with a desired portion of the corresponding conductive trace. For example, a mask used during the photolithography process must be precisely aligned with a substrate on which the contacts and conductive traces are to be formed, and the conditions and duration of the etching process must be accurate. If these processes are not controlled or accurate, the contact may not be formed in the desired location, preventing proper connection with the corresponding conductive trace and causing a short, which may lead to device failure or performance degradation. As device sizes continue to decrease, the margin of error in alignment and etching processes increases, making it even more difficult to accurately align the contacts and the conductive traces. As contacts decrease to sizes less than 40 nm, issues with alignment will become even more problematic.
It would be desirable to form contacts at sizes of less than approximately 40 nm using processes that are more robust and controllable.